It is proposed to continue with the preparation of H-2 congenic mouse strains, to look for H-2 recombinant haplotypes, to place the recombinants into inbred congenic backgrounds and to investigate their immunogenetic properties. It is planned to proceed with studies on the genetic control of alloimmune responses. BIBLIOGRAPHIC REFERENCES: David, C. S., Stimpfling, J. H., Shreffler, D. C. 1975. Identification of specificity H-2.7 as an erythrocyte antigen: Control by an independent locus, H-2G, between the S and D regions. Immunogenetics. 2:131-139. Dorf, M. E., Stimpfling, J. H., Benacerraf, B. 1975. Requirement for two H-2 complex Ir genes for the immune response to the L-Glu, L-Lys, L-Phe terpolymer. J. Exp. Med. 141:1459-1463.